Being mentally prepared is just as important as being physically prepared when it comes to a game of golf. This is the time to rid your mind of all of the stress and to focus solely on the game at hand.
Before hitting the golf ball, take a nice, deep breath. Doing this can clam you down a great deal and allow you to focus on the ball. There's no need to rush. Take a few seconds to imagine the ball's flight path before swinging. Take deep breaths to eliminate any tension in your swing.